BR-319 (Manaus-Porto Velho Highway)

node · earth · Amazonas and Rondonia

A federal highway built in the 1970s between Porto Velho and Manaus, abandoned to the forest within about a decade as maintenance proved impossible, and repeatedly proposed for reconstruction since. It is the most consequential road in the basin precisely because it does not currently work. Its corridor runs through the interfluve between the Purus and Madeira rivers - one of the largest remaining blocks of intact forest anywhere in the Amazon, containing indigenous territories and conservation units, and lying almost entirely outside the arc of deforestation. Reopening it would connect the cleared south to the intact centre-north, and the modelling consistently concludes that the clearance would follow the road rather than stay on it. It is therefore the single decision in which the abstract argument about tipping points becomes a specific choice about a specific two-lane road.